This invention relates to the structure of, and method of manufacturing, a solar battery output section for the purpose of extracting output from a solar battery device.
Prior art solar battery output sections have adopted structures as shown in FIG. 16 using a method of manufacture as follows. In FIG. 16, 301 is an insulating substrate made from resin material. On top of this substrate 301, conductive epoxy 302, a metal electrode layer 303, an amorphous silicon semiconductor layer 304, a transparent conductive film layer 305, conductive epoxy 306, and copper epoxy 307 are formed in layers. This region of the solar battery functions as an output terminal 300. After these layers are formed, a hole 308 is provided through the substrate 301 at the output terminal 300 of the solar battery. A thin metal foil 309 is then soldered above the copper epoxy 307 to cover the hole 308 via a solder layer 310.
Next, a protective resin film 311, which is covered on one side with an adhesive layer of resin that becomes plastic with heat (not illustrated), is applied with pressure and heat over the substrate 301 including the output terminal(s) 300. The entire solar battery is then flipped over and a wire lead 313 is soldered to the metal foil 309 via solder 312 within the hole 308. Fabrication of a prior art solar battery output terminal region is thereby completed by the processing steps described above.
The following problems exist with the prior art solar battery output section described above.
(1) When the entire solar battery is flipped over and a wire lead 313 is soldered to the metal foil 309, solder heat is transmitted to the metal foil 309. The protective resin film 311 covering the metal foil 309 is melted by that heat.
(2) Because of the thickness of the solder layer 310 and metal foil 309, and the thickness of the multi-layer structure of solder layer 310, metal foil 309, and copper epoxy 307, a large step results, and the protective resin film 311 can easily delaminate in this region (X in FIG. 16). Since this delamination is located on the light-receiving surface of the solar battery, it is undesirable from the standpoint of external appearance.
(3) To increase the electric power producing area of the solar battery, it is preferable for the hole 308, which is a non-electric power producing element, to be as small as possible. However, solder attachment of a wire lead 313 into a small hole 308 results in poor manufacturability.
The present invention was realized to solve these problems. The object of the present invention is to provide a solar battery output section and its method of manufacture wherein output is pulled from solar battery devices at the backside of the substrate, the protective resin film does not melt when wire leads are solder attached, the protective resin film does not delaminate, and manufacturability of the solder attachment process is good.
The above and further objects and features of the invention will be more fully apparent from the following detailed description, along with the accompanying drawings.